Non-woven fabrics are used in a wide range of fields such as medical materials such as masks, patches and the like, interior materials of automobiles such as ceiling materials, seats, and the like, agricultural materials, construction materials, civil engineering materials, in addition to battery separators, potable water filters, manufacturing filters, and the like.
Non-woven fabrics are produced by first forming a mass of long fibers or short fibers called a web, and next, bonding between the fibers. As a method of bonding between the fibers, a method of bonding between the fibers by melting by heating a part of the fibers is known. As such a method of producing a non-woven fabric by utilizing heating, for example, a thermal bond method, a melt-blown method, a spun-bond method and the like are known.
Investigation of thermoplastic resins constituting the web of fibers for producing non-woven fabrics is being carried out. For example, non-woven fabrics where the web of fibers is a composite fiber consisting of resins having differing melting points or glass transition points have been disclosed (Patent Documents 1 and 2).
Patent Document 1: Japanese Unexamined Patent Application, Publication No. 2013-049943
Patent Document 2: Japanese Unexamined Patent Application, Publication No. 2014-148774